1. Field of the Invention
The invention relates to a method for producing a cushion with at least one soft elastic region. In particular, the invention comprises a felt cushion with a silicone pad for use with orthopedic devices.
2. The Prior Art
It is known that such cushions are used in orthopedic devices such as epicondylitis braces. This is accomplished by using a felt cushion, which is adapted to the shape of the epicondylitis brace, and has silicone points in its end areas which come into contact with the skin of the user in a special manner, thereby preventing the cushion from slipping.
These felt cushions are produced by introducing a recess into the felt cushion and gluing a prefabricated silicone spot of the same size in this recess. Such orthopedic devices are known from WO 97/24085 and WO 99/09917.
An object of the present invention is to provide a method for producing a cushion for use with orthopedic devices which can be easily manufactured and is inexpensive.
The method according to the invention comprises injecting a free-flowing material into a cushion to form a soft elastic region, and solidifying the free-flowing material in the region. This makes it possible to produce a cushion with a soft elastic area rapidly, inexpensively and extremely easily.
A cushion having a recess is preferably placed on a supporting surface, and then the free-flowing material is introduced into the recess to form the soft elastic insert. The free-flowing material flows into the recess of the cushion and is then solidified. In this case, a cushion with a soft elastic insert is created in an especially simple and rapid manner, whereby the cushion and the soft elastic insert are bonded together. This takes place through the injection of the free-flowing material within the recess, whereby the free-flowing material flows to the cushion, adheres to the cushion and then is solidified. In this case, an insert with an exact fit is produced, in one operation, while at the same time being bonded to the cushion. As an alternative, a cushion without a recess can also be used.
In a preferred embodiment, the soft elastic insert is made of silicone, which is introduced into the recess in the form of a liquid and then vulcanized. In addition, it is advantageous if the free-flowing material poured into the recess is actively distributed. Essentially, it is also possible to have only the free-flowing material flowing in the recess. After a short period of time, a uniform layer develops. It is advantageous if the supporting surface is aligned to be absolutely horizontal. In another embodiment of the invention, the supporting surface is heated to approximately 70-120xc2x0 Celsius, so that the solidification of the material and the vulcanization of the silicone can be adjusted by the temperature setting. The vulcanization time of silicone amounts to between one minute and several hours, depending on the temperature and the catalyst content. It is preferred that the temperature be adjusted so that the vulcanization time is approximately two to three minutes, because otherwise the silicone will soak too deep into the cushion. At a vulcanization time of two to three minutes, the silicone runs to the edge of the recess and to the edge of the cushion and fuses with the cushion at the edges and vulcanizes fully. After the desired vulcanization time, the cushion is removed from the heated supporting surface to cool.
In an alternative embodiment, the cushion does not have a recess, rather it is designed as a continuous piece. This cushion is stretched on a cushion mount, which has a recess in the position where the region for forming the silicone pad is provided. The free-flowing material is poured into the recess of the cushion mount, and is vulcanized forming a cushion on which is arranged a pad extending above the cushion and fused with the cushion.
In another preferred embodiment, the cushion is stretched on a cushion mount having a recess aligned with the recess in the cushion. The cushion and cushion mount are placed together on a supporting surface. This is accomplished by arranging the cushion between the supporting surface and the cushion mount, i.e., the cushion rests directly on the supporting surface and the cushion mount is arranged above it. The cushion mount is mechanically secured so that it exerts a force on the cushion and the cushion rests on the supporting surface to seal it. The femur fracture material poured into the recess in the cushion and remains inside the recess and cannot escape through gaps. It is advantageous to use a cushion mount which is adapted in shape to that of the cushion. Therefore, not only is the recess exposed, but also the cushion can be pressed onto the supporting surface in the common area.
In another preferred embodiment, a soft coating is applied to one side of the cushion. This soft coating is designed with a hook strip, i.e. a VELCRO(copyright)-type closure. In this case, the cushion with the soft coating can be attached to the cushion mount with corresponding hook strips arranged on the cushion mount. The cushion is then placed on the supporting surface on the side opposite the side having the soft coating. Flush sealing silicone pads or silicone spots are produced on the side of the cushion on the bottom facing the supporting surface. The pads are in contact with the patient""s body, thereby preventing the cushion from slipping. The recess of the cushion mount is preferably filled with the free-flowing material to form the insert. Therefore, an insert can be designed thicker than the cushion itself, or with any desired height. The insert or the silicone pad preferably has a height of one to two millimeters.
This method can be performed such that several cushion mounts are operated simultaneously. Therefore, several cushions can be placed on the supporting surface at the same time and the free-flowing material is poured into the recesses in these cushions and solidified at the same time. In this way, it is economically feasible to produce large lot sizes.
In another preferred embodiment, the supporting surface is profiled so that the silicone regions produced can have a desired shape. Concave or convex designs of the heated contact surface are possible. A concave design of the supporting surface, i.e., a hollow or inward curving shape, is especially preferred, so that the silicone region is shaped with a convex curvature on the outside. Thus, on the whole this yields a felt cushion with a silicone region curving outward, projecting slightly and therefore it can contact the user""s skin especially well and thus prevent slipping.
A cushion having a soft elastic region, in particular a silicone pad, can be produced by the method described here, where the cushion is fused to the soft elastic region in a bordering area. This bordering area is preferably about 1 mm thick. The soft elastic region can be fused to the cushion on its lower side. As an alternative, the soft elastic region is fused to the cushion on its outer edge. Such a cushion is especially simple to produce, and it prevents separate gluing of the soft elastic region to the rest of the cushion.
Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings which disclose several embodiments of the present invention. It should be understood, however, that the drawings are designed for the purpose of illustration only and not as a definition of the limits of the invention.